Efeito da distância de transporte e condições climáticas sobre os indicadores fisiológicos de bem-estar dos bovinos

Abstract

The aim of this study was to evaluate the effects of transport distance on the welfare of male and female cattle transported to the slaughterhouse during rainy and dry season, from the hematological parameters and physicochemical analysis of the carcass. A total of 297 bovines Nelore and crossbred, being 147 females and 150 non-castrated males, with average weight of 187.5 and 277.5 kg and 24 and 32 months of age, respectively, coming from Tocantins farms. The animals were allocated in groups according to sex and distance traveled to the slaughterhouse: <50 km, 100-200 km, 201-300 km and> 300 km. Blood samples were collected during exsanguination for hemato-biochemical and the pH was measured in carcass after 24 hours of cooling (final pH = pHu). Transport over long distances cause increase in hematocrit and urea, creatinine and lactate concentrations. Also increase of the serum activity of creatine kinase (CK), aspartate aminotransferase (AST) and the pHu of the carcass. Sex interferes in some hemato-biochemical parameters and males had increased creatinine, higher serum activities of CK and AST and higher pHu of the carcass. Females had increased in hematocrit, urea, glucose and lactate values. The animals transported during the dry season had increase in albumin, creatinine, glucose, and high serum activity of CK and AST. The animals transported in the rainy season had increase in serum urea. The total proteins, hematocrit, lactate and pHu were affected both by dry and rainy season. In this case, some variables such as road quality, percentage of transport in unpaved road, total travel time, transport distance and the individual adaptability of the animals also had influence on their blood concentrations, impairing well-being. According to our results, transport over long distances interferes with well-being, causing dehydration and physical stress, resulting in increased pHu of the carcass, contributing to DFD meat. Sex also interferes with well-being and males were more sensitive to physical stress and muscle injuries. Females showed greater reactivity to effects of stress and less capacity to adapt to stressors. Animals transported during the dry season presented dehydration and increased emotional and physical stress. However, the animals transported in the rainy season had greater stress effects on protein breakdown.